The internet’s most important infrastructure is still largely out of sight—and increasingly exposed. Elisabeth Braw’s new book The Undersea War examines the cables, pipelines, and power links beneath the oceans that connect modern economies, as suspicious maritime incidents turn seabeds into another arena for geopolitical conflict.
Braw, a senior fellow at the Atlantic Council, focuses on the growing vulnerability of critical infrastructure in her new work, published by PublicAffairs in the United States and John Murray Press in the United Kingdom. The book explores a pattern of incidents involving ships whose anchors appear to have dragged unusually long distances, damaging communications cables and energy infrastructure from the Baltic Sea to the Pacific. Ars Technica’s report identifies those cases as a central concern of Braw’s investigation.
That concern is not based on the assumption that every cable break is an attack. The International Telecommunication Union says submarine cables carry more than 99 percent of international data exchanges, while the International Cable Protection Committee estimates that roughly 150 to 200 faults occur worldwide each year. Most are caused by ordinary commercial activity—especially fishing gear and ship anchors—with natural hazards and equipment failures accounting for additional damage.
The strategic problem is that routine accidents and deliberate interference can look deceptively similar. In the Baltic Sea, cables and power links were damaged in a series of incidents involving vessels including the Chinese-owned bulk carrier Yi Peng 3 and the tanker Eagle S. Investigations and legal proceedings have not produced one simple explanation for every case: some incidents remain contested, while Swedish authorities later concluded that damage attributed to the Vezhen was accidental. Reuters’ timeline documents both the sabotage suspicions and the uncertainty surrounding individual events. Reuters
The consequences extend far beyond slower internet service. Submarine networks carry financial transactions, cloud traffic, government communications, and mobile backhaul, while neighboring pipelines and electrical interconnectors support energy security. NATO says undersea cables carry approximately 95 percent of global data flows and support an estimated $10 trillion in financial transfers each day. That makes a damaged cable a potential communications problem, an economic disruption, and a test of national resilience all at once.
Governments are responding with more surveillance rather than relying solely on rapid repairs. NATO launched Baltic Sentry in January 2025, combining frigates, maritime patrol aircraft, drones, and shared monitoring to protect critical infrastructure in the Baltic. The challenge Braw’s book highlights is that the ocean remains vast, cable routes are difficult to guard continuously, and the line between negligence, opportunism, and gray-zone warfare may only become clear after the damage is done.
